Chemiluminescent immunoassay techniques generally comprise forming a reactive mixture of a known amount of antibody with a biological sample containing an unknown amount of antigen to be determined, or vice versa. A known amount of a competing immunoreactant, which is labelled with a chemiluminescent label, is added to the reactive mixture. The reactive mixture is incubated, the labelled immunoreactant competing with the sample immunoreactant for the known amount of the complementary reactant, as well known in the art.
After incubation, the excess unbound labelled immunoreactant is usually separated from the reactive mixture, and an oxidant is added to trigger the chemiluminescence of the bound labelled immunoreactant. The measured level of chemiluminescence is indicative of the amount of the antigen in the biological sample.
Chemiluminescent immunoassays require that very precise amounts of the various reagents and/or reactants be used, because of the usually low concentrations of the sample immunoreactant.
The invention has as one of its purposes to precisely control the amount of oxidant used to trigger the chemiluminescence, and to precisely and uniformly deliver the oxidant to the bound chemiluminescent immunoreactants to provide a more sensitive, accurate and precise immunoassay procedure.
Additionally, the invention teaches a method of performing chemiluminescent immunoassays in avoidance of the separation step, a usually inconvenient and time-consuming exercise.
The invention further seeks to teach conservation or reuse of some of the reagents or reactants for subsequent immunoassy tests, since many of the reagents employed are expensive.